1. Field Of The Invention
The present invention relates to a luminance interspersion type waveform display apparatus which successively samples a supplied waveform signal so as to store it in a memory. The apparatus connects between the sampling data items of the neighboring time-base addresses with a dot for linear luminance interspersion so as to store it in a bit memory. The apparatus then reads the memory in the direction of the time-base address by raster scanning so that the waveform of a dot pattern is displayed.
2. Description of the Prior Art
A luminance interspersion method which performs real time processing by using a hard logic circuit for the purpose of successively sampling a supplied waveform and linearly interspering the sampling dot data items of the neighboring time-base addresses has been disclosed in U.S. Pat. Nos. 3,902,476 and 3,812,491.
A conventional waveform display apparatus of the type described above is arranged in such a manner that the input waveform signal is successively sampled so as to store it in a memory. Then the stored waveform data is connected by dots for realizing a linear luminance interspersion and the waveform is displayed after transmission to a bit map memory to be read in response to raster scanning. According to the conventional apparatus, the luminance interpolation data is processed by an operation of a CPU so as to be temporarily stored in an exclusive memory. Then, the corresponding address in the bit map memory is addressed so that it is transmitted.
According to the above conventional apparatus, the reading of the bit map memory is restricted by a scrolling function where the display position is shifted from a normal position in the direction of the time base to the newly sampled waveform portion which is displayed in the reverse direction of the time-base.
As a result, circuit processing in the conventional device is too complicated and completion of the processing has taken an excessively long time. Furthermore, when waveforms of a plurality of channels are displayed, the structure of the circuit becomes extremely complicated if the scrolling is not performed common to all of the channels.